branches/2d/examples/walls/circle.cc

   1 #include "voro++_2d.hh"
   2 using namespace voro;
   3
   4 const double pi=3.1415926535897932384626433832795;
   5 const double radius=0.95;
   6
   7 // This function returns a random floating point number between 0 and 1
   8 double rnd() {return double(rand())/RAND_MAX;}
   9
  10 int main() {
  11         int i;double x,y;
  12
  13         // Initialize the container class to be the unit square, with
  14         // non-periodic boundary conditions. Divide it into a 6 by 6 grid, with
  15         // an initial memory allocation of 16 particles per grid square.
  16         container_2d con(-1,1,-1,1,10,10,false,false,16);
  17
  18         // Add circular wall object
  19         wall_circle_2d wc(0,0,radius);
  20         con.add_wall(wc);
  21
  22         // Add 1000 random points to the container
  23         for(i=0;i<1000;i++) {
  24                 x=2*rnd()-1;
  25                 y=2*rnd()-1;
  26                 if(con.point_inside(x,y)) con.put(i,x,y);
  27         }
  28
  29         // Output the particle positions to a file
  30         con.draw_particles("circle.par");
  31
  32         // Output the Voronoi cells to a file, in the gnuplot format
  33         con.draw_cells_gnuplot("circle.gnu");
  34
  35         con.print_custom("%i %q %a %n","circle.vol");
  36
  37         // Sum the Voronoi cell areas and compare to the circle area
  38         double carea=pi*radius*radius,varea=con.sum_cell_areas();
  39         printf("Total circle area       : %g\n"
  40                "Total Voronoi cell area : %g\n"
  41                "Difference              : %g\n",carea,varea,varea-carea);
  42 }